Hydrosilylation

Why choose Johnson Matthey for your hydrosilylation needs?

Johnson Matthey supplies the largest selection of platinum-based hydrosilylation catalysts on the market. These are used in diverse specialist applications like baking moulds and dental impressions. Our range of high-quality catalysts has been produced with different cure characteristics to help with a variety of applications and where appropriate, grades for specific customer applications.

We can formulate Karstedt solution to control catalyst concentration, stability, viscosity and inhibition. Our Karstedt catalyst is a pale solution designed to give exceptionally low turbidity on the formulation. The high Pt concentration allows additions of small quantities of catalyst to formulation batches.

Easy formulation and less waste

Due to the tight control of our development and manufacturing processes, Johnson Matthey platinum group metal catalysts for Hydrosilylation (e.g. Karstedt catalyst) have a consistent level of activity with minimum variance from batch to batch. Such low variance makes it easier for you to formulate, avoiding waste of catalyst and incomplete reactions.

Attention to health & environment

During manufacture, our Karstedt products are carefully controlled to minimise any residual platinum compounds which might have adverse characteristics to health and the environment.

Homogeneous catalysts for hydrosilylation

Platinum compounds are extremely active catalysts for hydrosilylation. Originally, chloroplatinic acid (CPA) was used as a hydrosilylation catalyst (sometimes known as Speier’s catalyst). However, this compound is a potent sensitiser and is hazardous to health. Read our Comparative hazardous properties profile for CPA and Karstedt catalyst (1MB PDF file opens in new window).

Heterogeneous catalysts for hydrosilylation

When a homogeneous hydrosilylation catalyst is used, the platinum usually remains with the reaction products. This can cause issues of cost, colour and safety depending on the end application.

As well as homogeneous catalysts such as Karstedt catalyst, Johnson Matthey also offers heterogeneous catalysts for hydrosilylation reactions. These enable the catalyst to be filtered from the product thereby avoiding these concerns. Generally, a higher loading of catalyst will be needed than for the corresponding homogeneous catalyst. However, the reaction may be smoother with better exotherm control and it is often possible to re-use the catalyst.

This catalyst is 0.1% platinum as Karstedt in 500 cS polydimethylsiloxane. It is used for the addition curing crosslinking reaction between Si-vinyl and Si-H groups. Karstedt catalyst promotes a quick, low temperature curing in the formation of silicone elastomers.

This catalyst is 10% platinum as Karstedt in 200 cS polydimethylsiloxane. It is used for the addition curing crosslinking reaction between Si-vinyl and Si-H groups. Karstedt catalyst promotes a quick, low temperature curing in the formation of silicone elastomers.

This catalyst is 10% platinum as Karstedt catalyst in 1000 cS polydimethylsiloxane. It is used for the addition curing crosslinking reaction between Si-vinyl and Si-H groups. Karstedt catalyst promotes a quick, low temperature curing in the formation of silicone elastomers. Johnson Matthey can provide formulations to meet specific requirements for activity, stability and viscosity.

Benefits

• Platinum is in the zero oxidation state with no co-ordinated chlorides

This catalyst is a solution of platinum as Karstedt in 1000 cS vinyl terminated polydimethylsiloxane. It is used for the addition curing cross-linking reaction between Si-vinyl and Si-H groups. Karstedt catalyst promotes a quick, low temperature curing in the formation of silicone elastomers.

This catalyst is a solution of Karstedt. It is used for the addition curing cross-linking reaction between Si-vinyl and Si-H groups.This stabilised Karstedt formulation provides a long pot life plus rapid curing with low product yellowing when heated.

This catalyst is a solution of Karstedt catalyst in 1000 cS vinyl terminated polydimethylsiloxane. It is used to cross-link silicone polymers in two-part RTV addition-cure silicone systems. Karstedt catalyst promotes a quick, low temperature cure in the formation of silicone elastomers.

This catalyst is a solution of Karstedt catalyst in 1000 cS vinyl terminated polydimethylsiloxane. It is used to cross-link silicone polymers in two-part RTV addition-cure silicone systems. Karstedt catalyst promotes a quick, low temperature cure in the formation of silicone elastomers. Johnson Matthey can provide formulations to meet specific requirements for activity, stability and viscosity.

This catalyst is a solution of platinum as Karstedt in 500 cS vinyl terminated polydimethylsiloxane. It is used for the addition curing cross-linking reaction between Si-vinyl and Si-H groups. Karstedt catalyst promotes a quick, low temperature curingin the formation of silicone elastomers. Johnson Matthey can provide formulations to meet specific requirements for activity, stability and viscosity.

Benefits

• Platinum is in the zero oxidation state with no co-ordinated chlorides

This catalyst is a solution of Karstedt catalyst in 500 cS vinyl terminated polydimethylsiloxane. It is used to cross-link silicone polymers in two-part RTV addition-cure silicone systems. Karstedt catalyst promotes a quick, low temperature cure in the formation of silicone elastomers. Johnson Matthey can provide formulations to meet specific requirements for activity, stability and viscosity.

Benefits

• Platinum is in the zero oxidation state with no co-ordinated chlorides

Ashby’s catalyst solution is a Pt(0) complex in tetramethyltetravinylcyclotetrasiloxane. It is used for the addition curing cross-linking reaction between Si-vinyl and Si-H groups. The highly stable catalyst solution provides a long pot life with rapid curing at elevated temperatures.

Benefits

• Platinum is in the zero oxidation state with no chlorides coordinated

This catalyst is a solution of Karstedt. It is used for the addition curing cross-linking reaction between Si-vinyl and Si-H groups.This stabilised Karstedt formulation provides a long pot life plus rapid curing with low product yellowing when heated.

BenefitsRh-93 is used to catalyse hydrogenation and hydrosilylation reactions. Rhodium catalysts can be more resistant to poisons than platinum ones for hydrosilylation. It can also be used for isomerisation, hydroformylation, carbonylation, polymerisation and reductive amination.

This catalyst is a low concentration solution of platinum as Karstedt in 500 cSt vinyl terminated polydimethylsiloxane. It is used for the addition curing cross-linking reaction between Si-vinyl and Si-H groups.

If you cannot find Karstedt catalyst in our catalogue, which would be suitable for your application, please contact our Technical team with information on your specific requirements by selecting "Karstedt catalyst other" in the Product field.